v2025.12.0

This release rolls back the default engine for HTTP urls, adds support for DataTree objects in combine_nested and contains numerous bug fixes.

Thanks to the 16 contributors to this release:
Benoit Bovy, Christine P. Chai, Deepak Cherian, Dhruva Kumar Kaushal, Ian Hunt-Isaak, Ilan Gold, Illviljan, Julia Signell, Justus Magin, Lars Buntemeyer, Maximilian Roos, Miguel Jimenez, Nick Hodgskin, Richard Berg, Spencer Clark and Stephan Hoyer

What's Changed

• new release section by @keewis in #10926
• Fix numpy typing issue with numpy=2.3.5 by @shoyer in #10935
• support combine_nested on DataTree objects by @shoyer in #10849
• [pydap backend] enables downloading multiple dim arrays within single http request by @Mikejmnez in #10629
• Fix flaky Hypothesis stateful test for unique name generation by @max-sixty in #10946
• normalize the first indexer by @keewis in #10948
• Mostly restore netcdf backend behavior with URLs by @ianhi in #10931
• Adapt to change in behavior of pandas.Timestamp constructor by @spencerkclark in #10944
• DOC: Correct many grammatical issues by @star1327p in #10959
• avoid casting custom indexes in Dataset.drop_attrs by @keewis in #10961
• Fix type annotation for DataVariables to use Hashable instead of Any by @dhruvak001 in #10960
• Coerce IndexVariable to Variable when assigning to data variables or coordinates by @jsignell in #10909
• (fix): handle internal type promotion and nas for extension arrays properly by @ilan-gold in #10423
• Migrate development workflow to Pixi by @VeckoTheGecko in #10888
• Fix workflow name to embed matrix.pytest-addopts by @VeckoTheGecko in #10970
• Add GitHub Codespaces config for Pixi by @VeckoTheGecko in #10929
• small changes to the pixi env definitions by @keewis in #10976
• Use ._data in Variable._replace by @dcherian in #10969
• Support decoding unsigned integers to timedelta by @dcherian in #10972
• DOC: Remove RTD htmlzip output format by @VeckoTheGecko in #10977
• document limitations of cftime arithmetics by @larsbuntemeyer in #10653
• DOC: Add llms.txt generation to build process by @VeckoTheGecko in #10978
• release v2025.12.0 by @keewis in #10981
• set the release date by @keewis in #10984

New Contributors

• @larsbuntemeyer made their first contribution in #10653

Full Changelog: v2025.11.0...v2025.12.0